Percussion tool for wells



May 16, 1950 R. BASSINGER PERCUSSION TOOL FOR WELLS 5 Sheets-Sheet 1 Filed July 26, 19

INVENTUR ATTORNEYS y 1950 R. BASSINGER 2,507,585

PERCUSSION TOOL FOR WELLS Filed July 26, 1946 3 Sheets-Sheet 2 I3 l3 l4 L L L 76? 84 z 9:? Es -87 E Fir iii? L [00 23W 0] R055 BASS/NGER uv VENTOR AT TORNEYS 5 Sheets-Sheet 5 Filed July 26, 1946 ill/Ill rill/Illa?!" R F. 6 N 5 5 A B 5 5 .I 0 2 m R I 3 3 3 2 6 Cl 39 0] 2 ww ww m If .1 $111 G El 787 8 mfimm m /N VE N TOR ATTORNEYS 'ourren'oe'. v

lay-the completion ofa well with the'correspondi 'atented May 16 1950 1 "UNI-TED j STATES not o-FaFicE 2,507,585

PERoUssIoN' T0013 FOR Ross Bassinger, Houston; Tex. Application .T'ulv 2'6, 1946, Serial No. 6869197" This inventionfrel'o-tes to new useful immovements in percussion tools for wells.-

' i It has been a wide-spreadoccurrence inthe dr-iil'ing industry, thdt in drilling wells in "certain'locali ties or fieldsgvery-hard and rooky for- "mations are sometimes encountered which are ---drilled' before it is necessary to pullthe tubing andreplace the bit, being a fairly common ocbviou's-ly, such conditionsgreatly dein'g increase in expenses; is well as creating "highly undesirable collateral conditions which are not tevorable to: the driller.

-Heretofore, various percussion type bits have been developed and tried in drilling operations.

At the present time, none of these bits have proved successful or answered the need for a drilling: assembly' capable of efficient operation under: the unfavorable-conditionsusuallyencouni 'tered, or. even under favorable conditions. In-

some instances; attempts have been made to use e cejble tool; type bit, but necessarily; such opyera tions were not satisfactorwafteri a'ceit'ain '.depth:of hole-liadbeenobtained;

. It" therefore, one: o'bj ect of this invention to 'provide' ztn improved percussion tool adaptable for: use with a drill bit, which is: effective and operative under normal co'nditionswithin a; well bore, to deliver a seriesf hard blows to f a" drill bit; or to other-suitable tools end' 'oonnections" within a drill string. I

It'is an important object of the invention to provide an improved percussion tool for" use" in wells;- which? is responsive to flow of the'drilling fluid through a well conductor to deliver inter mittent blows: of. considerable magnitude and forceto aa drill bit,.orz other connection inthe drilling string.

A further object of the invention is to-provide .animproved percussion tool having hammer which is givenmomentumby the flow ofithe drilling fluid and with which blows of considerableintensity and magnitude may be delivered to a'suiteble connection in e. drillingstring".

his a; particular object-of the inventiontoproto a tubing? connection; 0I'"a," fishing tool, or' any other 'suitabiee'lement in the drilling string; and whichmawbewenderedinoperative-or operative '7 blaims. (01. 255-27) *s'ity areideliveredbythehirnmerto a driil -bitpr othersuiteble' rhe'ansi v'ide an improved percussion tool "for wells which maybe utilizedesaijar 'todelivera' series'ofblows i berets uniform di met vide er'c iieected eponbytiie not liiemni at will without the are f the di illiiiig s'iirifig 'f-rom-thewellboiie be ng-necessitate L 7 Yet another object of theinventioii i'sto provide an improved percussion-tour for use iI-f-WllS, said tool be-i-ng 'res' 'porisiv Wofthe annffi'uid to "deliver a seriesofb-lows'bf considerable magnitude and intensity; and being with acaIoie tooltiwe bit," whereby a well Still another obll'cf wherein the upper end nd pressui-e ofthdhlling fluid to impartedownwara inipiid's .toti-ie f; one wnerem-means are provided co-octing with the1113381 b1" the Iittrr'llriifil' tdiit "ajl'so' toth'e drilling flu endmove d wnwardly as does the hammer; SaJi-dl'a'ttr means being stopped end returned to its upward position be ore the 'heiniinerhes completed its ownward travel under to momentumimperted thereto; soas to'receive the returner the latter to itsj'upward position aud t-o omments a subsequent downward travel of said hammer. whereby'interinittehtfblows of considers-151m Yet another-object of the invention i'S' to prof woiror dse'in'wells money and maemtudeor inten- "'s'ity ofthe tmvts'aeiivereu by the toormey e controllediby theoperetcr.

v A construction designed'to carry 'oii't'th'e invention" will be hereinafter described together with otherfeatnres *oftne' iiivention;

The inveiitiori will'fbe more refdily gn erstood from e reading"of-the follo'w'irig' specification nd by reference to-the c ompanying dre. n's, wherein an e'x'a'mpl'e of the invention is siiown,

and wherein": Y

Fig; i is a longitudinalviewpertiyifi eleveticn and partly insietibn'; or percussion tool constructed mg eccor once with" thisinvention, ano snowin' the' nammer raisedp sitio Fig: 2 no continuationofr'lg; 1, snowingtfie lower end ofine-1x301,"

Fig: 31s View elevition-of thediiili bit, tes neti-ignt angles to Fig. 2. 7

131 i is ajbott view of the-drill bit;

ntai; orbs's sebtionel view taken Fig. 8 is a horizontal, cross-sectional view taken on the line 88 of Fig. 1,

Fig. 9 is a horizontal, cross-sectional view taken on the line 99 of Fig. 2,

Fig. 10 is a longitudinal view of the upper end of the tool, partly in elevation and partly in section, and showing the hammer and control sleeve in a lowered position,

Fig. 11 is a longitudinal View, partly in elevation and partly in section, and showing a modified form of the tool,

Fig. 12 is a View similar to Fig. 11 showing the elements of the tool in a lowered position,

Fig. 13 is a horizontal, cross-sectional view taken on the line l3--l3 of Fig. 12,

Fig. 14 is a horizontal, cross-sectional view taken on the line I4l4 of Fig. 11,

Fig. 15 is a horizontal, cross-sectional view taken on the line I5-I 5 of Fig. 11,

Fig. 16 is a horizontal, cross-sectional View taken on the line Iii-16 of Fig. 11,

Fig. 17 is a horizontal, cross-sectional view taken on the line I l-l 1 of Fig. 11,

Fig. 18 is a longitudinal view, partly in elevation and partly in section, and showing a jar made in accordance with the principles of this invention,

Fig, 19 is a longitudinal view, partly in elevation and partly in section, and showing a modification of the jar shown in Fig. 18,

Fig. 20 is a horizontal, cross-sectional view taken on the line 20--20 of Fig. 18,

Fig. 21 is a horizontal, cross-sectional view taken on the line 2 l-2l of Fig. 18,

Fig. 22 is a horizontal, cross-sectional view taken on the line 22 22 of Fig. 19, and

ing string and by which th conductor is suspended in a well bore. The extreme lower end of the pin I2 is reduced in diameter to form a depending skirt M. Radial ports I5 extend outwardly through the walls of the skirt I 4 to provide circulation of the drillin fluid between the skirt and the inner walls of the conductor l0, and to permit the drilling fluid to fiow therebelow.

The conductor I0 is provided with a longitudinal bore I6, which is reduced slightly in diameter at a point spaced below the upper end of the conductor so as to form an internal annular shoulder ii. A cylindrical sleeve l8 has a snug fit within the bore of the conductor and is provided at its upper end with a laterally-extending external shoulder 19 Which engages the shoulder I! carried by the bore I6, whereby the sleeve is supported within the conductor. An internal, annular flange 20 is formed upon the lower end of the sleeve l8 and a coiled spring 2! is supported upon said flange. A ring 22 is disposed above the upper end of the spring 2| and urged into engagement with the lower edge of the skirt [4 by the compressive force exerted by the spring. The ring 22 carries a plurality of notches 23 about its outer periphery, and an elongate, tubular control sleeve 24 depends from the center portion of the ring.

The ring 22 has a sliding fit within the bore l6 whereby the ring and the sleeve 24 are free to move upwardly and downwardly with respect to the conductor 10, the upward movement of the control sleeve being limited by engagement of the ring 22 with the lower edge of the skirt l4, and downward movement of the sleeve being limited by engagement of the ring with the upper end of the sleeve [8.

A plurality of elongate slots 25 are provided in the side walls of the sleeve 24 to permit circulation of the drilling fluid therethrough. The control sleeve is provided at its lower end with an internal, annular, beveled flange or annulus 26.

An elongate, cylindrical hammer 28 is positioned within the conductor 10 below the control sleeve 24, and being of considerable length and diameter, is very heavy. Obviously, the hammer may be hexagonal or square, or have any other suitable cross-sectional configuration. The lower end of the hammer is positioned above the lower end of the conductor and is cut at right angles to the longitudinal axis of the hammer to form a flat head or striking face 29, the edge of which is bevelled, as is customary in such hammers.

The outside diameter of the hammer is somewhat less than the inside diameter of the conductor l0, so that an annular space 30 is provided therebetween. A plurality of elongate fins or shoes 3| are formed at intervals upon the surface of the hammer, and serve to center the hammer within the bore of the conductor, as is shown in Fig. 8 of the drawings. The upper portion of the hammer is provided with longitudinal flutes 32 for allowing circulation of the drilling fiuid, and an elongate reduced cylindrical piston 33 extends axially of the extreme upper end of the hammer. In the position shown in Fig. 1 of the drawings, the upper end of the piston 33 engages within the annulus 26 of the control sleeve 24.

A plurality of laterally-extendin fins or lugs 34 are secured upon the lower portion of the piston 33 and extend outwardly into sliding engagement with the bore of the conductor. The outer lower corners of the fins 34 are cut away to receive an annular ring 35 which is carried upon a coiled spring 36 encircling the fluted portion of the hammer. The lower end of the spring 36 is carried upon an annular ring 31 supported upon a plurality of lugs 38 extending inwardly from the wall of the conductor Ill. The lugs 38 are shown in the drawings as being separate elements set into the wall of the conductor, since this is a much simpler and more economical method of making such a structure.

In this manner, the lugs 38 support the ring 31, the spring36 and the ring 35, which in turn supports the fins 34, the piston 33 and thereby the hammer 28, The hammer is free to move upwardly and downwardly within the bore of the conductor within the limits set by the adjoining elements of the tool.

The bore [6 is enlarged slightly near the lower end of the conductor NJ to form a downwardlydirected shoulder 39, which receives an annular bevelled ring 40. A pressure-responsive packing ring 4!, equal in diameter to the ring 4! is disposed beneath said ring and held in snug engagement therewith by a spacer collar 42 positioned beneath the packing ring. The extreme lower end of theconductor carries internal screw-threads 43 which receive the screw-threaded pin 44 of a retaining collar 45. The upper end of the pin 44 a so-mas the paclnng ring 41" imposition. V

ins-bit;- carrier AB- .isa'di'sp'osed at the "lower tend of the -conductor l0. and is'zprovidedfwithi an en- 'largett having a: tapereiiscrew threaded within-the complementing-grooves 53 and 54 110 pnevent rotative movement of the" bit carrier ifi with-respect to-the retaining collar 45.

ris is shown in Fig. 2 of the drawings, the

gnooves 53- tormed upon} the shank 49' are-somewhat longer than the splines '55 carried therein, *so that the carrier 'may undergo limited longitudinal movement with respect to the collar 45 and the conductor l0, while being held against i'otation with respect thereto. This structure makes'provision for protecting the conductor- I andf the tubingstring-upon which it is supported "from theshoek' ofthe blow delivered tothe anvil H -by the hammer"28.

bit 56,-whichmay beofany desirable type, V screw-threadedpin- 51 engaged within" the "b0 48-, whereby the bit' is rigidly securedto-the -B'it carrier'AB. It has been found preferable to use acable tool type bit which isnot subjected to "undue-wear at its outer corners due to hard formations, and thereby insures the operator. of a *Well bore-of uniform diameter. Thebit is'provid'e'dwith the usual drillingflui'd passages- 58 "through which the drilling fluid may flow.

The importance of making provision in this tool-for using any desirable type of bit, is stressed. l fler'ttbforej thefew attempts to'provide aperou's'sion drilling mechanism'have utilized rock 'drills, such as star drills,- to penentrate the hard formations encountered, and have experienced 'considerable difiicultyin maintaining the" diamter otthe well bore. In the present invention, tliis 'malfunction is eliminated and a-well bore 'of substantially uniform diameter is'obta-ined.

AI-tlioug'lra cable tool type bit is suitable and fllcient, other types of bits may beutilized-with- -i-lfthe scope of this invention.

'Inthe operation of this device,the entire assembly-is lowered into" the W811 bore upon the usualdrilling string (not shown) until the bot- -torn-of the hole is reached. A certain amountof weight-upon the bit is desirable to cause the splines55 to ride downwardly "within the grooves 53. The lower end of the retaining collar-45 res-ts *jtipori' the-enlarged head-"41 of the bit carrier to -"place weight on the bit and protect the splines. "Upon-starting the mud pump (not shown) ,dri-ll- 'fing fluid or-mud is circulated downwardly through the drilling string under pressure, and passes "throughthabore' of the collar 13 and pin -12 ihtd"the-interiorof the control sleeve 24. The drilling-fluid may also flow through the ports I5 {and slots 251:0 insure ample circulation about the-spring 2| and within the annular space bethe control' sleeve and the conductor.

- pressure at the tool; which" maybe anyith mg fildm iseveral. hundred-1tgpounds'ztoarastthoii rsanduor soz;.poundsz,perssquare inchactsunponiith'e zupper end of .thepistonvilt and: alsunponathecomtrolssleevezflaSinceithe spring Zleissnotz asntrong ;orstiff :as themfspring itifi, the control isleevesisis ierced td'ownward'ly :compressi ng. thergspring '2 l "Due to the pressure soft the idril'lingirfinid,rithi's idownward. movementsis very arapid rand Z'QBGUEIS very quickly. The-ccontroliisleeve *travelszcfownzwardly untihtheiring iflwengages the npperizend rot the sleeve l8; at whichfitimepifnnther strewn,- :W-ardi movementaoflitheassleeve istprevented;

"The downwardimovementtofsthe:controlesleeve rrelievesto some extentthapressure: ofithedrill'mg fluid acting zuponl the piston and: diverts; the

flowo-fithe fiuid' 'thereirom. ificwever; asisoonsas the sleeve reachesi-the bottom f-ofisirfs stroke, the full 'pressure of the drilling fluid'ras awellras cthe ""i mpact-resultant from itsmomenturmis' directed u-pon the piston, thereby forcing the: piston and hammerdowrrwardIywins-great rapidity; soias t'o impart considerable velocity: and momentum to the hammer.

The weight of i the entire column of ('i'riIl-ing fiuid within the-tubing string is behind tl'iis- 'impact, so that -there'is no hesitationiinthe 'fi'ow of i the 'drilling 'fluid, the force: brought to bearon' the hammer beingtsiitrrcient to: eliminate an-y delay in its downward movement.

the hammer moves 'downwardly, the piston is withdrawn from 'thebore' 21. When-this acct-11B,

thedrii-ling-fiuid is permittedto flow throughcthe here into the lower part ofi thetooLwhilethe ham- 'mer continuesits downwardtravel'un r'momen- 'tu-m-until the face '29' strikes the'anvil il and delivers a blow thereto-,which is transmittedthrough the bit c'arrier-BG to the' 'bit 56. As soonas this blow-is delivered;- and the momentum of the ham- "The piston iswithdrawn from the bore i I -beforethe' hammer strikes the anvil. otherwisegea *fiu-idlock would occur and' the operation of'thedevice be impaired if n'ot termi-natedaltogether.

' -Howeven the time intervalor' the distance trav- 1 very' 'small g sol: that the hammer deliversizits blow elled by the 'hammer': after suchwithdrawahii's at substahtially peak momentum and-r velocity. By varyihg the dimens'ionsiand hence therspacing of the e'lements for iexampleiby increasingreor decreasing the length of: the :pist 011233,: the: frequency a-hd m'aLgnitude ioffitheliblowsi struck: can :be controlled.

It is-not necessary that theipistnnhave.azzclose within'thecontrollsleeve. @1311 Fig. 23iiscshowfn a modification of theseielements:inlwhichthe pis- "ton- 53 iSTCOIISidEIabIyiZIGSSL sin diameterathan the sl'eeve; andnaportioneoittherdrilling fluid-pressure the drillingilfluidrwouldifiovwat all; times through the annular space hetweene thexlpi'ston:oontrol "thus idissipated. i'Neveitheless, suffictentpressure and -'-vol'umet ofedrilling; fluid would: remain to operate the tool effectively.

Nor is it necessarysthatthe comroli'sleevelreach the-E lon'reri end -ofsiits stroke :rbeforez .the;.: hammer starts to move downwardly. thespringiz is compressed; theibaclvpressure-on the pistenrv ereases. The 'criti'cal; tame-1 necessary tossta-rt 'downward rmovement of ftherhammerzzmay ebe reach ed as-: the xsleeve .znearspithe'ivhottom JiOf.,.-EitS --strokeg so that when;the-isleevewreachesfitsslower- 1mm? positiom downward movement dnthe ham-- 'mer hasatready commenced.

It cannowbe seen that when the'p'iston 3315 within the .bore 21, the housing [[3 is divided into a low pressure chamber below the bore 21 as viewed in Figure 1 and a high pressure chamber above the bore 21 as it is viewed in that figure.

It is pointed out, that as soon as the piston has been withdrawn from the bore .21, the pressure acting upon the control sleeve is relieved through the bore 21 in the annulus and the sleeve is returned to its upper position by the spring 2|. As the hammer is returned to its upper position by the spring 36, the piston is moved into the .bore 21 and the control sleeve immediately moved downwardly by the pressure of the drilling fluid so that a second cycle is commenced. The design and proportions of the various elements of the tool control, to some extent, the frequency of the impact cycles. Several hundred blows per minute upon the anvil 5! may be obtained, and

due to the considerable mass of the hammer,

these blows are of large force and power.

It is also pointed out, that as the hammer moves upwardly, the drilling fluid exerts an increasing pressure upon the control sleeve whereby the sleeve may start its downward stroke or travel before the piston and hammer reach their uppermost position. Thus, at this moment the sleeve and the piston would be moving in opposite direc- :tions. This function is dependent upon the de- :sign and proportions of the various elements. In :any event, the sleeve would start its downward travel as soon as the piston enters the bore 27.

In drilling operations, the drilling string may be rotated at the same time that mud is being pumped downwardly through the string, so that the bit 55 is rotated over the surface being drilled, and at the same time, several hundred blows of considerable magnitude are delivered each minute through the lower cutting edge of the bit to the formation. In this manner, very fast and efficient drilling of extremely hard formations is obtained while preserving the other desirable characteristics of rotary drilling. A

Itis to be noted, that the flow of drilling flui through the entire tool and out through the ports 58 of the bit 56, is never interrupted so that a .continuous lubricating and flushing action is maintained. This worth-while result-is obtained by reason of the structure of the piston and control sleeve. trol sleeve on its upward travel, communication through the bore 21 is reduced or minimized; but, the sleeve immediately starts to move downwardly, thereby displacing drilling fluid therebelow. And, as the sleeve nears or reaches the lower end of its stroke, the hammer is moved downwardly displacing additional fluid. This action is very rapid, and by this means fluid continues to move downwardly at all times during the cycle. The frequency of the cycles is sufliciently high to insure very little pulsation of the drilling fluid.

In Figs. 11 through 1'7 of the drawings, is shown a modification of the invention which operates upon the same principle as the first form described, but has certain of the elements rearranged in different combinations.

In this form of the invention, the control sleeve 24 is replaced with a control plunger or piston,

while the piston-type hammer is replaced with a tubular or sleeve-type hammensaid elements to be described hereinafter. The tubular conductor 60, of this modification of the invention, is divided into an upper section BI and a lower section 62 connected by a screw-threaded joint 63 at their adjacent ends. Theupper conductor 6| carries As soon as the piston enters'the coninternal screw-threads 64 at itsiupper" end which engage the screw-threaded pin 65 of the collar 66 by which the tool is connected to the usual tubing or drilling string (not shown). The upper section 6| is provided with a longitudinal bore 61 which is reduced in diameter at a point spaced above the lower end of the section to form a shoulder 68 and a reduced bore 69. The extreme lower end of the section 61 is bevelled at 10 for purposes to be set out hereinafter.

A ring 12 is disposed above the shoulder 68 and carries a plurality of radially directed fins or supporting members 13 formed integrally of the ring and extending downwardly therefrom to engage the shoulder 68, whereby the ring is securely held against downward movement with respect to the upper section ill. The axial bore i l of the ring has its upper portion counterbored at #5 to receive the lower end of a sleeve l6 having a bore Ti substantially equal in diameter to the bore 14 of said ring. The sleeve '16 is provided at its upper end with a plurality of radiallyextending fins or lugs '58 which engage beneath the pin E5 of the collar 66 to secure the sleeve and the ring 72 against upward movement. A pair of diametrically opposed, longitudinal slots is extend throughout the upper portion of the sleeve.

A cylindrical control piston 86 has a sliding fit within the sleeve it and is greater in length than the sieeve, the lower end of the piston being enlargecl to form a head 81 which extends below the ring 12 and engages therebeneath. A transverse slot 82 is formed near the upper end of the piston fill and receives a cotter 33 which extends through the slots 19 of the sleeve 75. The lower sides of the projecting ends of the cotter are cut away to receive an annular ring 84 which encircles the sleeve 16 and engages within the cutawa portions to prevent displacement of the cotter from the slot 82. A coiled spring 85 is compressed between the ring i2 and the ring 84 so as to urge the cotter 83 and the piston upwardly at all times.

A tubular hammer 86 having an axial bore 81, has a sliding fit within the bore at and extends therebelow within the bore 88 of the lower conductor section 52. The upper portion 89 of the bore 3? is enlarged slightly in diameter so as to have a snug sliding fit with the head iii of the piston 80, said enlarged portion extending downwardly a distance substantially equal to the length of the slots 18. The hammer is provided at spaced intervals throughout its length with a plurality of radially extending external fins or lugs 9?; which serve to center the hammer within the bore 88 of the lower section of the conductor and to guide the hammer in its travel therethrough. A plurality of spaced, radial ports 36' cut in the lower portion of the wall of the hammer allow proper circulation of the drilling fluid and prevent the fluid from cushioning th hammer blows. 7

- Internal screw-threads 9! are formed at the extreme lower end of the lower conductor section to receive the screw-threaded pin iii of a retaining collar 92 similar in all respects to the collar it shown in the firstform of the invention. A spacer collar 93,'similar to the collar 12, is disposed upon the upper end of thepi-n en andcarries an; annular, pressure-responsive packing ring 94 upon which rests a packing retaining sleeve 95. The sleeve Eta-has asnug fit within the bore 88 and is formed with a bevelledinwardly-directed flange -96 at its lower end, said flange serving to retainithe paokingzring:84- in position. The sleeve extends upwardlyzto a .pointspaced. slightly above thQilOWGI'aQIl-dzOf therhammer 1&6 .whensaid. hammer is :in its upper position, land .a;.plurality of inwardlyedirected .fins or Jugs 9-1 are provided upon .the :upper end of thesleeve. The hammer has a sliding --.fit within said .lugs, and :a coiled spring-:98.is'compressedvbetween the lugs 91 and the lugs :96 carried-by the hammer, so thatthe spring =constantly tends to urge the hammer upwardly. The upward movement of the hammer is. limited-by engagementof the lugs '90 with the lower end-of the .uppersection 6 I.

A-bit'holder (notshown) is positioned in the lower endof this modificationnfthetool,.and is provided with an upwardly-extending shank .99 havingan axial bore I00. The shank 9.8 issplined to the-retaining collar B2 zby means of-cylindrical roller splines .Hil similar to the splines 55 described BiIIathG'fiIStiOI'm of the invention. The axialbore mil extends throughout the length of the shank fit, and the upper periphery of said shank .isadapted to act as ananvil-to receive impactblows delivered through the lower periphcry-5 of the hammer.

Theoperationof this modified form is substantially the sameas that set out in connection-with the...descri ptionof-the first form of the invention. Drilling .fluid under pressure acting downwardly through the collar acts upon the control piston 80 to force itdownwardly against the compressive forceof the.sprin ..85. The downward travel of the .control piston is limited by engagement of the cotter with thehottoms of the slots I9. As the control piston nears or reaches the lower-end of itsstroke, the pressure of the drilling fluid acts vuponrthe upper end of thehammer to drive it downwardly under .considerablevelocity. Due tothe heavy-walledconstruction of the hammer, great .momentumis thereb acquired to deliver a heavy blow. As the hammer moves downwardly the engagement of the head .8! .withinjthe enlarged bore 890i. thehammeris terminated and the drilling. fluid iree to.flow .around the lugs '13 and below thering 14 to enter into the .axialbore of the hammer. When this separation .occurs, the control piston .is free to be returned to its upper position by thespring 15 while the hammer continuesdownwardly under momentum to .deliver a blow.to the upper end of theshank 99 of thebitIhoIder, whichhlowis communicated directly to the cutting edges of the bit (not shown). This .bit .is similar in all respects .to that shown in..the, first .form I of the invention, and may be rotated through the splines I OI while percussion blows are. being struck so as to. effect acombination,,percussion androtary drilling action.

,As soonas the hammer has ,deliveredits blow, thespring '98 returnsit to itsrupper position, the bevelITIlfacilitating-the entry of the hammer into the bore 69 wherein the head =8I of the control piston. 80 again. engages within the .upper portion 89.0f the bore .of the hammento trapJthe drilling fluid and commence thedownward. movement 7 of the. control piston. Thacycle thus repeats itself indefinitely-untilsuch time as pumping of the drillingfluidisstopped.

,InEigs. 18,20 and21-of thedrawings, is shown a jar constructed in accordance with the principles .of ..this invention. Such .a toolhas a wide variety of .useabeing employed extensively in fishing .operations wherein it is d esiredto impart tolthetubingl string aseries of upward: blows in order to dislodge alength-coiitubingor various oil well tools whichmay become stuck within iii the :well born. .The tool is .adapted tobe used in connection .with .a variety of fishingtools which engage the.stuckobjects in various manners and usually requirea-series of upward blows to loosen or free the. stuck object, or itmay be usedin any other instance wherein it is desirable to employ .a ar.

.In this :form of .the invention, .an .upper conductor section "I III, similar -.to the upper-section 61 of themodifiedform .of the invention shown in Fig. 11 -of-the-.drawings, is utilized, and a lower section II I,-similar.to'the lower section 62 is .provided. Internal screw-.threads-I I2 are provided in the upper-end of thelowersection, which engage a screw-threaded upin 113 formed on the lower end of the upper-section H0. A piston H4 is carried upon -.a -.coiled spring I I5within theupper section; Hi1. in-the' same manner that the control pistonis carried within theupper section-62. The: piston .I I4 is similar in all respects to the piston .80 with the exception that the lower end of the piston II-fl'is not enlarged toxformahead, but has'a continuous:-externalsurface. Thelower edge of the piston is rounded to facilitate its.engagement' within the hammer to be described hereinafter.

The lower portion *I-Ilof the wall of the upper conductor section I Hi is increased-in thickness to providezareducedaxial'boreI I8 within whichthe control piston reciprocates, and ,a plurality of longitudinal grooves I I-9;square;in cross-section, areriormed-inthe-wall of the bore .I I8 to permit circulation of idrillingfiuidtherethrough.

'Thethickened wallsection in the lower'endof the upper section Illl'prov-ides an anvil adapted-to be struck by :a heavy cylindrical hammer 420 which has asliding fit within-the lowerconductor 580171011 11! The hammer is formed with an-axial bore I 2-l "extending throughout its length and :in which the control :piston H4 has a slidingfit. The outside diameter of the hammer is reduced in the lowerxportion of the hammer to form .a tubularsshank: I 22 Aand'an external annular, downwardly-directed shoulder I23. A plurality =01? radialfiportsY-lid are :formed in the wall --of the shank I22 to permit circulation of the -.drilling fluid.

"Internalscrew threads are provided upon the extreme flower end of "the lower-conductor section III and receive the screw-threaded'pin I26rof a'retain'ingcollar I21. Enlarged, internal, screw-sthreads I28 are :provided within the :collar I21 .and :engage similar threads I29 formedon the upstanding pin I30 of a coupling collar 1:31. The collaracarries the usualscrew-threaded pin 1-32 on its lower end, and is-provided with an upstanding-tubular'sleeve I33 extending above the screw-threaded pin'ltll. The lower end of the shank [22 of the hammer telescopes the .upper end of the sleeve "I33, and a coiled spring I34is compressed between the upper end of the sleeve and the shoulder I23 formed on the hammer. A suitable split safety ring I 35' is positioned within an external,;annulargroove I EB formed at the upper end of the sleeve, so -as'to prevent complete disconnection of the coupling collar I3I from the. retaining collar IZ'I whenthe threads I28and .I29 aredisengaged. Thering I35 may be formed of .any suitable frangible or shearable material so that it maybe.- sheared to release thetool in the .event .thestuck object andthe fishing tool cannot be freed. ...Also, an internal, annular groove t3l-is provided :in the bore of the retaining collar lflabove .the:-.screW-;threads I28 and receives an annular packing ring I38 to pack off the joint between the retaining collar and the sleeve I33.

In the operation of this modification of the invention, the tool described is connected into the fishing string above the fishing tool, and may be located at any desirable point within said string. Upon circulation of drilling fluid through the string, the control piston I I4 is forced downwardly by the pressure of this fluid, compressing the spring H5. The downward travel of the control piston is limited by a cotter, structurally corresponding to the cotter 82 shown in Fig. 11, so that the pressure of the drilling fluid forces the hammer downwardly under momentum. As the hammer separates from the control piston, the piston is returned to its upper position by the spring I I5 and the hammer continues downwardly until its momentum is absorbed by the spring I34, which is thereby p'laced under considerable compression. This compressive force is released from the spring by the rapid return of the hammer to its upper or impact position. The spring forces the hammer upwardly with considerable momentum against the lower end of the pin I I3, and delivers a blow of considerable force and power to said pin, the blow being transmitted through the lower section III, the retaining collar I21 and the coupling I3I to the tubing and/or fishing tool or other appliance below this percussion tool.

Here again the hammer I23 and the piston I M when engaged subdivide the interior of the casing into a high pressure chamber above the valve and a low pressure chamber below it.

Thus, the drilling fluid serves to compress and store energy in the spring I34, which, when released, drives the hammer upwardly into violent impact with the lower end of the pin II3, which impact is transmitted to the fishing tool. The tool may be designed to deliver a relatively high frequency of impact blows, as many as several hundred per minute, and the force and frequency of these blows may be further controlled by means of the enlarged screw threads I28 and I29.

These threads, being of relatively coarse design, may be partially disengaged with considerably less torsional force than the normal threaded connections in a tubing or fishing string. The tubing may thus be rotated from the well head to rotate the lower conductor section III. The tubing below this percussion tool is held against rotation by the fishing tool, so that the collar 'I3I is held. The rotation of the tubing in the well head therefore results in' a breaking of the joint between the pin I30 and the retaining collar I21. This operation moves the sleeve I26 along with the spring I34 downwardly with respect to the upper section I I0 and the control piston I I4, and allows the hammer to move downwardly with respect to the control piston due to its own weight. When the hammer is in its upper position, the spring I34 is in its fully expanded position, taking the weight of the hammer into consideration, so that such separation allows the hammer to move downwardly as described. The moving apart of the control piston and hammer causes complete disengagement of these two elements earlier in the impact cycle so that blows of less force are delivered to the pin or anvil H3. Continued rotation of the tubing will completely separate the hammer and control piston, so that circulation of the drilling fluid is established between or through the space between the two elements, and the tool is rendered inoperative. Thus, the operator may establish circulation of the drilling fluid to the fishing tool, or to a point 12 below this percussion tool, without causing the tool to operate and deliver impact blows. When desired, rotation of the tubing may be reversed to again bring the control piston into engagementwith the hammer and resume operation of the tool. It is pointed out, that the jar is normally run into the well in this inoperative position so as to prevent the necessity of displacing fluid in the well bore. After positioning the tubing may be rotated to bring the jar into operation.

In Figs. 19 and 22, is shown a modification of this jar in which a control sleeve I49, similar to the control sleeve 2i; described in connection with the first form of the invention, is utilized. The upper conductor II is constructed similarly to the section IIU shown in Fig. 18, with the eX- ception that the bore I42 replaces the bore H8 and the grooves I I3, and is of sufiicient diameter to receive the control sleeve I48. A tubular, heavy walled hammer Ie3 is slidable Within the lower conductor housing Ida, the bore I45 of the hammer being closed at its upper end by an upstanding reduced piston I45 which is adapted to be engaged by the control sleeve I40. A plurality of ports IQ'I communicate between the bore I 45 of the hammer and the space at the base of the piston I46, so that circulation of the drilling fluid downwardly through the hammer may take place. A screw-threaded pin I48 is provided at the lower end of the upper conductor section I i-I to form an anvil adapted to be struck by the upper end of the hammer as the piston I455 telescopes thev bore I42 and control sleeve I40.

The operation of this last form of the invention isthe same as that described in connection with the immediately preceding form. The hammer and control sleeve are forced downwardly in rotation by the drilling fluid until disengagement vof the two elements occurs. The hammer continues to travel .downwardlyuntil the energy of its momentum is absorbed by the spring, at which time energy thus stored in the spring is released to force the hammer upward rapidly, causing it to strike the pin or anvil I48 under considerable momentum and thereby deliver a blow of sizeable magnitude.

In each of the modifications described, the same provisions apply as for the first form disclosed. It is not necessary for the pistons and sleeves to fit closely, and, if desired, considerable clearance may be provided between the two, as shown in Fig. 23. It is important that the two elements separate before the hammer blow'is struck, and to obtain maximum power it is desirable that the blow be struck immediately after separation. However, the hammer may travel greater distances before impact, the loss in power being proportional to the delay after separation and before impact.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the invention.

. What I claim and desire to secure by Letters Patent is: V H

1. A well percussion tool that comprises a tubular housing means having an axially directed opening therein dividing the interior of said housing into an upper high pressure chamber and a low pressure chamber below the high pressure chamber, an opening into the high pressure chamber for the supply of high pressure fluid thereto, an opening from the low pressure chamber for the exhaust of fluid therefrom, two elements mounted for axial reciprocation within said housing, one of said elements having the form of a sleeve fitting slidably in the opening in the means dividing the housing into upper and lower chambers, the other of said elements having the form of a piston fitting slidably in said sleeve; elastic means for urging one of said elements toward the high pressure chamber, means to urge the other member toward the high pressure chamber, said elastic urging means and said other urging means causing said elements to engage to close the opening between the chambers so that a pressure differential may be established to force the elements in the other direction; a hammer attached to one of the elements; and an anvil mounted on said housing below said elements and serving to stop the movement of said hammer and the element attached to it in a direction away from said high pressure chamber, after said element having the hammer attached thereto has passed out of engagement with the other element thus releasing the pressure differential between the chambers and allowing the other element to move back toward said high pressure chamber.

2. A well percussion tool comprising a tubular housing, sliding sleeve and piston elements reciprocally mounted in said housing for individual movement in the same direction from a telescoping position dividing the housing into a high pressure chamber and a low pressure chamber to a mutally separated position in which communication is established between said chambers, said housing having a drilling mud inlet to said high pressure chamber and a mud outlet from said low pressure chamber, an elastic means biasing one of said elements toward said inlet, means biasing the other of said elements toward said inlet, both of said elements having surfaces exposed to the pressure of said high pressure chamber, the area of said surfaces being correlated with the thrust of the biasing means so that the element which effects the separating stroke moves in response to a higher pressure than the other element, and impact receiving means in the path of movement of the element which effects the separating stroke between its separation from the other element and the re-establishment of telescoping relation thereto.

3. A well percussion tool comprising a tubular housing, sliding sleeve and piston elements reciprocally mounted in said housing for movement in the same direction from an upper telescoping position dividing the housing into a high pressure chamber and a low pressure chamber to a lower position in which the piston is withdrawn from the lower end of the sleeve, said housing having a drilling mud inlet to said high pressure chamber and a mud outlet from said low pressure chamber, a high thrust spring biasing said piston toward said inlet, a low thrust spring biasing said sleeve toward said inlet, said sleeve and piston each having a surface exposed to the pressure of the high pressure chamber, the area of said surfaces in relation to the thrust of the respective springs being such as to cause the sleeve to move in response to a lower pressure than the piston and impact receiving means in the path of reciprocation of the piston between the, egress thereof from the lower end of the sleeve and the re-entry thereof into said sleeve to which the piston element imparts a blow.

4. A well percussion tool comprising a tubular housing, sliding sleeve and piston elements reciprocally mounted in said housing for individual movement in the same direction from an upper telescoping position dividing the housing into a high pressure chamber and a low pressure chamber to a lower position in which the sleeve is withdrawn from around the lower end of the piston, said housing having a drilling mud inlet to said high pressure chamber and a mud outlet from said low pressure chamber, a high thrust spring biasing said sleeve toward said inlet, a low thrust spring biasing said piston toward said inlet, said sleeve and piston each having a surface exposed to the pressure of the high pressure chamber, the arrangement of said surfaces in relation to the thrust of the respective springs being such as to cause the piston to move in response to a lower pressure than the sleeve, and impact receiving means in the path of reciprocation of the sleeve element between the separation thereof from the lower end of the piston and the return thereof into piston-surrounding position to which the sleeve element imparts a blow.

5. A well percussion tool as claimed in claim 2 wherein the impact receiving means is an anvil connected to the casing near the lower end thereof and in which the mud outlet from the lower pressure chamber includes a passageway through the anvil.

6. A well percussion'tool as claimed in claim 3 in which the sleeve is provided with longitudinally extending ports therethrough for a portion of its length, the low thrust spring surrounds the sleeve and means are provided for dividing the mud flow entering the inlet into a portion surrounding the sleeve and a portion within the sleeve.

7. A well percussion tool as claimed in claim 2 wherein the impact receiving means is an internally projecting shoulder constituting a part of the housing and acting to receive the stroke of the element effecting the separation in its movement toward the mud inlet.

ROSS BASSINGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,076,469 Travers Oct. 21, 1913 1,861,042 Zublin May 31, 1932 2,245,786 Johnson June 17, 1941 2,344,725 Phipps Mar. 21, 1944 

